Far too many people employ the torpedoes incorrectly. A tail chase is a good example. Most pilots boresight a ship as though the torpedo is a rocket (I see this everytime I man a 5" gun). They launch and I'm sure wonder why the torpedo seems to miss after the drop. The ship sails by leaving the torp in its wake. Airplanes and PT's need to lead their targets - a lot. When you think your aimpoint is far enough in front of the ship, add some more.
However:
A key thing to remember is that torpedoes do not have to actually hit a ship to be effective.
Torpedo runs by bombers and PT's are great ways to force a fleet to turn. Done correctly, successive attacks can heard a fleet away from an area if the fleet skipper is vigilant in trying to protect his ships.
Forcing a carrier to turn also makes it very hazardous to the airplanes trying to take off. Many pilots run off the sides or hit the superstructure during the take off roll. Smart pilots wait til the ship starts to straighten out. Keeps air ops minimized.
MiG